At present, in the field of flat panel display technology, a TFT liquid crystal display (referred to as TFT-LCD for short) has advantages such as a small size, low power consumption and relatively low manufacturing cost, and gradually dominates today's flat panel display market.
Current TFTs are mainly amorphous silicon TFTs and organic TFTs, a fabricating method of which includes sequentially depositing, on a substrate, various film layers having different properties such as an active layer, a dielectric layer, a metal electrode layer and the like, and forming respective patterns. With the development of the TFT-LCD technology, a technique of oxide thin film transistor (OTFT) has become more and more developed. The OTFT technique has advantages such as high carrier mobility, low power consumption and applicability to low frequency driving, and in particular, it can be applied to organic light emitting diode display apparatus known as the next generation display technology. However, as compared to a conventional process, the fabrication process of OTFT is more difficult in implementation, and its procedure is complicated in that it typically requires a patterning process for more than six times, which will greatly limit the capacity of a production line.
How to optimize the fabrication process of TFTs, especially OTFTs, and reduce the steps of patterning processes, has become an urgent technical problem to be solved.